Today, I've been investigating a series of reports about some miners having zero hashrate. The reports seem to be all over the place. Some people state that their miners display zero hashrate in the live worker status pane, while others state that they aren't being credited money for some workers. As a result, I can't figure out whether the issue is a display issue or a mining server problem that needs investigation. Most of the reports seem to involve SHA-256 miners, so I wonder if this could be related to the sudden decline in SHA-256 hashrate recently.

Has anyone experienced zero hashrate or "no valid shares yet" issues for one worker despite all the other workers displaying fine?